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Diffstat (limited to 'mm/vmstat.c')
-rw-r--r--mm/vmstat.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c
index f389168f9a83..355a9e669aaa 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -138,11 +138,24 @@ static void refresh_zone_stat_thresholds(void)
int threshold;
for_each_populated_zone(zone) {
+ unsigned long max_drift, tolerate_drift;
+
threshold = calculate_threshold(zone);
for_each_online_cpu(cpu)
per_cpu_ptr(zone->pageset, cpu)->stat_threshold
= threshold;
+
+ /*
+ * Only set percpu_drift_mark if there is a danger that
+ * NR_FREE_PAGES reports the low watermark is ok when in fact
+ * the min watermark could be breached by an allocation
+ */
+ tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
+ max_drift = num_online_cpus() * threshold;
+ if (max_drift > tolerate_drift)
+ zone->percpu_drift_mark = high_wmark_pages(zone) +
+ max_drift;
}
}
@@ -813,7 +826,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
"\n scanned %lu"
"\n spanned %lu"
"\n present %lu",
- zone_page_state(zone, NR_FREE_PAGES),
+ zone_nr_free_pages(zone),
min_wmark_pages(zone),
low_wmark_pages(zone),
high_wmark_pages(zone),
@@ -998,6 +1011,7 @@ static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
+ refresh_zone_stat_thresholds();
start_cpu_timer(cpu);
node_set_state(cpu_to_node(cpu), N_CPU);
break;